This document defines and classifies articulators based on their adjustability and ability to simulate jaw movements. It describes the parts and requirements of mean value articulators, which have fixed condylar guidance and incisal guidance. Mean value articulators are useful for mounting dental casts to simulate jaw movements and plan treatments without patient cooperation.

1. Zool khader shabana
Articulators

3.  Definition
 Classification
 Parts of an articulator
 Requirements of an articulator
 Uses of an articulator
 Advantages of an articulator

4.  A mechanical device that
represents the tempero-mandibular
joints and the jaw members to
which the maxillary and mandibular
casts may be attached to simulate
some or all mandibular movements

5.  Articulators are classified as:
1) Based on university of
Michigan workshop in 1972
2) Based on theory of
occlusion
3) Based on the adjustability of
the articulators
4) Bergstrom classification
of articulators

6. Class 1
Class 2
Class 3
Class 4
2a
2b
2c
3
a
3
b
4
a
4
b
articulators

7. Simple holding instruments capable of accepting
single static registration, e.g. hinge joint
articulator

8.  Instruments which permit both horizontal and
vertical motion. It is divided into three sub
classes
 Class 2a: eccentric motion permitted bis based
on average or arbitrary values, e.g. bonwill theory
articulators, simplex designed by Alfred gysi
 Class 2b: eccentric motion permitted based on
theories of occlusion, e.g. monson’s articulator
 Class 2c: eccentric motion permitted is
determined by the patient using engraving
methods, e.g. the house articulator

9.  Instruments that simulate the condylar pathways
by using average or mechanical equivalent values
for all part of the motion. It is divided into sub
classes.
 Class 3a: they accept a static protrusive
registration and use equivalents for other
movements, e.g. Hanau model H, Hanau
H2,Dentatus,Bergstrom articulator
 Class 3b: they accept a static lateral registration
and use equivalents for other movements, e.g.
trubyte articulator, panadent, the kinoscope,
stansberry (tripod-type) articulator, Ney
articulator, Hanau 130-21, Teledyne articulator

10.  These are instruments which accept three
dimensional registration. It is divided into two
sub classes.
 Class 4a: the condylar pathway is recorded by
the patient throughengraving methods and it
cannot be modified,e.g. the TMJ articulator
 Class 4b: this is similar to class 4a but they
can be angled or customised ,e.g.
gnathoscope , the denar ( D4 A) fully
adjustable articulator

11.  1. Bonwill theory articulators: It was designed by WGA bonwill
based on this theory of occlusion which stays that “ the
distance between the condyles is equal to the distance
between condyle and the midpoint of the mandibular
incisors”. It is also known as the Theory of equilateral
Triangle. Theoretically the dimension of the triangle is 4
inches
 2. Conical theory articulators: it was proposed by RE hall. The
conical theory says that the lower teeth move over the
surfaces of the upper teeth as over the surface of the cone,
generating an angle of 45 degrees to the occlusal plane
 3. Spherical theory articulators: this theory proposes that the
lower teeth move over the upper teeth over a surface of
sphere with a diameter of 8 inches.the centre of the sphere
was located in the region of glabella. Monson’s articulator is a
good example based on spherical theory of occlusion.

12.  The articulators based on the adjustability
features like:
 Acceptance of centric relation records
 Acceptance of face bow records
 Acceptance of lateral records
 Adjustable inter condylar distance

13. Articulators
Non adjustable
Semi adjustable
Fully adjustable

14. They can open and close
in a fixed horizontal
axis. They have fixed
horizontal path. The
incisal guide tables are
fixed. They can accept
fixed centric relation
record.
 Non adjustable
articulators
These articulators have
adjustable horizontal
condylar paths, incisal
guide tables and inter
condylar distance. These
articulators can be
further divided as Arcon
and Non Arcon
articulators.
 Semi adjustable
articulators

15. This term Arcon was
derived by Bergstrom from
the words articulating and
condyle. The condylar
element is attached to the
lower member whereas the
condylar guidance is
attached to the upper
member of the articulator.
This articulator resembles
the TMJ, e.g. Hanau series
and Whip Mix articulator
These articulators are
vice versa to the arcon
type. In these
articulators the condylar
elements are attached to
the upper member and
the condylar guidance is
attached to the lower
member, e.g. Hanau H
series and Dentatus
 Arcon articulators:  Non Arcon articulators:

16.  1. It should hold the casts in established horizontal
and vertical relationship
 2. It should provide a correct anterior vertical stop
 3. The casts should be reattached accurately
 4. It should Always open and close in the same hinge
movement.
 5.It should have enough space between the upper
and lower segment
 6.The upper and lower members should be always
parallel
 7. It should be made of non corrosive and rigid
material and resist wear and tear
 8. The moveable parts should be non rigid and non
moveable parts should be rigid

17.  Mean value articulator: Mean value articulator
has a fixed condylar guidance of 33 degrees
and incisal guide table
 1. upper member
 2. lower member
 3. incisal guide table
 4. vertical incisal rod
 5.central pin
 6.condylar guide
 7. stabilizing rod

18.  The upper member is a triangular frame with
base of the triangle placed posteriorly and
two condylar elements seen projecting on
either of the base. The apex of the triangle is
seen anteriorly and it has provision to hold
the incisal rod with a central pin. The vertical
incisal rod can be locked with the help of a
thumb screw. The maxillary cast is mounted
to the upper member during articulation.

19.  The lower member of the articulator consists
of two components, one the horizontal frame
and the vertical frame. The horizontal frame
is triangular in shape and corresponds to the
lower member. In the centre the lower
mounting plate attached. The anterior aspect
of the horizontal frame houses the incisal
guide table. The upper part of vertical frame
houses the condylar guide.

20.  They are two in number, one for the upper
member and other for the lower member. The
mounting plates are attached with the help of
thumb screw to the articulator. The upper
and lower casts are attached to the articulator
with the help of mounting plates

21. Incisal guide table determines the incisal
guidance of the articulator. The upper surface
of the incisal guide table is concave and the
vertical incisal rod should be in centre during
the articulation. The depth of the concavity is
designed to have a slope equal to the average
of 15 degree incisal guide table.

22.  Vertical incisal rod helps to maintain a fixed
distance between the upper and lower
member. It has a pointed tip which should
rest in the centre of incisal table during
articulation. The positioning of the incisal pin
can be adjusted with the thumb screw
attached to the upper member.

23.  At the mid point of the incisal rod there is a
hole provided to fix the central pin. The tip of
the central pin corresponds to the anterior
plane of occlusion during articulation. During
teeth setting the incisal edge of the maxillary
incisors should be in contact with the central
pin.

24.  Condylar guide guides the movement of the
condyle. In a mean value articulator, the condyle
guidance is in two parts, which are condylar track
and condylar element. The condylar track is
located in the lower member, inclined at an angle
which is average inclination of condylar guidance
(33 degrees) of the population. The condylar
element is seen projecting out from the base of
the triangle of the upper member. A spring is
placed within the track to hold the condylar
element in their most posterior position.

25.  Some mean value articulators have the
provision of attaching the stabilizing rod. It is
of help to the dentist during his work. It helps
to stabilize the member of the articulator,
while it is kept open

26.  To stimulate the patients TMJ movements and mandibular movements
 Mounting the dental casts in fixed relationship
 Mounting the dental casts for proper diagnosis, treatment planning and
presentation to the patient
 To help in fabrication of fixed and removable restorations
 To arrange artificial teeth
 To correct and modify the existing restorations

27.  It is helpful in visualizing the patient's occlusion
with much more ease, especially the lingual
occlusion
 Patient cooperation is not needed while using the
articulators because the articulator itself provides
the necessary movements
 It is more comfortable and there is refinement in
the work, as there is no disturbance like shifting
of denture base or resiliency of the soft tissues
 Reduced chair time with the patient
 Role of patient's saliva, tongue, cheeks and
posture is avoided.